Residents say passing trucks and buses feel "like an earthquake" with Sumner traffic being diverted along Celia St and Beachville Rd, while Main Rd is closed for the next four weeks.

Celia St resident Rick Zawodny said there was a constant flow of cars from 7am to 8am on the normally quiet road.

"When buses or any big trucks go past, it feels like a 2.5 earthquake," he said.

Resident Tamara Voucher said her house would often shake when a bus or truck went past.

"It feels like an earthquake... things kind of move," she said. "It's a lot noisier than normal."

She had been woken up at 5am that morning by trucks going past, she said.

The detour had been split to ease traffic woes of the 10,000 to 12,000 cars that use Main Road each day.

Sumner-bound traffic was being diverted along Beachville Rd, while city-bound traffic was being diverted down Celia St.

Some Celia St residents were unhappy as this meant they needed to go round Beachville Rd to get to their houses.

A SCIRT spokesman said closing Main Road was the only option as there was no alternative route to access the narrow patch of road where a new watermain was being installed. To slow traffic, 30kmh speed limit signs had been put in place, as well as the two traffic islands, the spokesman said.

But residents said many drivers disregarded these signs.

"They do tend to speed quite a bit... I won't let my children out unless one of us is out there," resident Ian Mulling said.

"When trucks go past it feels like the whole house is rumbling," he said.